COVID-19 vaccine acceptance among health care workers in Africa: A systematic review and meta-analysis

Introduction Coronavirus Disease (COVID-19) vaccine acceptance, and hesitancy amongst Health Care Workers (HCWs) on the African continent have been examined through observational studies. However, there are currently no comprehensive reviews among these cadre of population in Africa. Hence, we aimed to review the acceptance rate and possible reasons for COVID-19 vaccine non-acceptance/hesitancy amongst HCWs in Africa. Methods We searched Medline/PubMed, Google Scholar, and Africa Journal Online from January, 2020 to September, 2021. The Newcastle-Ottawa Quality Assessment tool adapted for cross-sectional studies was used to assess the quality of the retrieved studies. DerSimonian and Laird random-effects model was used to pool the COVID-19 vaccine acceptance rate. Sub-group and sensitivity analyses were performed. Reasons for COVID-19 vaccine hesitancy were also systematically analyzed. Results Twenty-one (21) studies were found to be eligible for review out of the 513 initial records. The estimated pooled COVID-19 vaccine acceptance rate was 46% [95% CI: 37%-54%]. The pooled estimated COVID-19 vaccine acceptance rate was 37% [95% CI: 27%-47%] in North Africa, 28% [95% CI: 20%-36%] in Central Africa, 48% [CI: 38%-58%] in West Africa, 49% [95% CI: 30%-69%] in East Africa, and 90% [CI: 85%-96%] in Southern Africa. The estimated pooled vaccine acceptance was 48% [95% CI:38%-57%] for healthcare workers, and 34% [95% CI:29%-39%] for the healthcare students. Major drivers and reasons were the side effects of the vaccine, vaccine’s safety, efficacy and effectiveness, short duration of the clinical trials, COVID-19 infections, limited information, and social trust. Conclusion The data revealed generally low acceptance of the vaccine amongst HCWs across Africa. The side effects of the vaccine, vaccine’s safety, efficacy and effectiveness, short duration of the clinical trials, COVID-19 infections, limited information, and social trust were the major reasons for COVID-19 hesitancy in Africa. The misconceptions and barriers to COVID-19 vaccine acceptance amongst HCWs must be addressed as soon as possible in the continent to boost COVID-19 vaccination rates in Africa.


Introduction
The current Covid-19 pandemic is a global public health emergency that offers significant challenges to health-care systems (1,2). ''Coronaviruses are large, enveloped, positive-strand RNA viruses that can be categorized into genera; alpha, beta, delta and gamma, of which alpha and beta are known to infect humans'' (3). Human Corona Viruses (HCoVs) i.e. HCoV 229E, NL63, OC43 and HKU1 are endemic globally and account for 10%-30% of upper respiratory tract infections in adults humans (3).
The current basic reproductive number (R0) of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS COV-2) is estimated to be three and as a result the threshold of herd immunity for COVID-19 is roughly around 67 percent (4,5). This purport that after the population's acquired immunity reaches 67 percent and above, COVID-19 infection rates will start to decline (6).
Individual and community initiatives such as enhanced hand cleanliness, physical distancing, and the personal protective equipment are currently being used to reduce disease transmission.
However, with the world facing an economic downturn and the future uncertain, a COVID-19 vaccine is perhaps the best option for halting the epidemic (7,8).
The SARS Cov-2 Development and Access Strategy established by Africa Center for Disease Control in 2020 aim to vaccinate at least 60% of African Population by 2022 to develop herd immunity (9). Africa has received approximately 143 million doses in total as of September, 2021, but only 39 million people, or around 3% of the continent's population, had been adequately vaccinated. In the United States, 52 percent of people are fully vaccinated, whereas in the European Union, 57 percent are (10). The willingness of HCWs to be vaccinated against COVID-19 acts as a valuable role model for the general public (11).
As the covid-19 vaccine becomes more widely available in Africa, Sevidzem Wirsty and colleagues (12) discussed and evaluated probable factors linked with vaccination acceptability in Africa as; ''Vaccine hesitancy, attitude and uptake by health care workers, misinformation, religion, immunization roll out plans, social influences and enabling environment'' (12). Vaccine aversion among the general public has a direct association to vaccine hesitancy among HCWs.
Thus, HCWs role in vaccine acceptability cannot be underestimated as a result of their modeling behavior (13).
A rapid systematic review of global vaccine acceptance among Health Care Workers (HCWs) ranged from approximately 28% to 73% (6). Similarly, a comprehensive review and meta-analysis of cross-sectional studies of health workers' intentions to vaccinate against covid-19 indicated a moderate acceptance rate [ i.e., 51 percent]. The authors did admit, however, that the population studied were largely from economically developed countries, which limited the study's generalizability (14). Clearly, this cannot be extended to represent HCW intentions to vaccinate against covid-19 in Africa.
Covid-19 vaccine acceptance, and hesitancy amongst HCWs on the African continent have been examined through observational studies. (7,15

Protocol registration and best practice
The Center for Reviews and Dissemination standards were followed in preparing this systematic review and meta-analysis (16). Also, the current review was conducted and reported according to the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) (17) [see S1 Table]. The protocol was registered at PROSPERO: [CRD42021275065]

Participants/Population
The participants were Health care workers as well as health science students from Africa continent, and adults HCWs (≥18 years] were included. HCW is operationally defined as; Doctors, Nurses, Pharmacists, allied health professionals, paramedics, and Healthcare students [i.e., medical students, nurse students etc.]. General population, other university students, and children were excluded.

Intervention/Exposure
The total number of health workers surveyed, number of health workers intending to receive vaccination against COVID-19, and COVID-19 vaccine acceptance rate were included. However, non-COVID -19 vaccine acceptance studies or covid-19 acceptance studies in the general population were excluded.

Types of studies
All primary studies such as longitudinal, cohort, case-control and cross-sectional studies reporting covid-19 vaccine acceptance and hesitancy among health care workers in Africa were included in the current review. Original observational studies published in English.
Studies reporting animal studies, reviews, commentaries, letter to editors. Covid-19 vaccine acceptance and hesitancy articles published in other language other than English. Covid-19 acceptability studies among health care workers outside the Africa continent [i.e., Asia, Europe, America, and Australia continents] were excluded.

Outcome of interest
The outcome of interest was covid-19 vaccine acceptance/and hesitancy rate among HCWs in Africa. In addition, the reasons for covid-19 hesitancy were explored.

Information sources and Search strategies
Medline/PubMed, Google Scholar, Africa Journal Online, and MedRxiv (preprint) were searched.
The search was restricted to studies published between January,2020 to date. The search was limited to articles published in English. Reference lists of articles that meet the inclusion and exclusion was checked to identify extra studies that were not captured by our electronic search.
Medical Sub-Heading (MeSH) terms and free text were used in the search approach. These terms were combined with the Boolean operators 'OR' and 'AND'. The key term includes; Covid-19, Vaccine, Hesitancy, acceptance, Health care worker, Africa, Sub-Saharan Africa. The full search string is shown in S2 Table.

Data screening and selection
The data screening and selection involved the following; Two co-authors [MA and LA] independently screened the titles and abstracts against the eligibility criteria. Full texts of the articles were then obtained against the inclusion and exclusion criteria. A disagreement was then resolved by consensus. To ensure that independent reviewers apply the selection criteria reliably, a screening guide was used (18).

Data extraction and management
MA and LA extracted the data from the eligible published articles using a pre-tested and standardized excel spreadsheet. Data such as the author's name, year of publication, country, survey period, study design, sample size, HCWs population, acceptance rate, questionnaire and, reasons for covid-19 acceptance/hesitancy rate were extracted. Mendeley was used to managed and remove duplicated articles.

Quality assessment and risk of bias
The Newcastle-Ottawa Quality Assessment tool adapted for cross-sectional studies (19) was used to assess the quality of the retrieved studies. It is graded on 10-point stars. This process was done by two independent reviewers and average was taken as a final score for that particular study. The  Table. The pooled vaccine acceptance among the HCWs was estimated using DerSimonian and Laird random-effects model (REM) at 95% confidence interval and presented in a forest plot. The presence of heterogeneity among studies was quantified by estimating variance using the I 2 statistics.
A sub-group analysis was performed based on sub-region (West Africa vs. East Africa vs. Southern Africa vs. North Africa) and type of participants (Healthcare workers vs. Healthcare students). Leave one out sensitivity analysis was performed to examine the effects of a single study on the overall pooled estimate. Publication bias was checked by the funnel plot and Egger's test

Results
The electronic search yielded 513 articles; 400 articles remained after the duplicates were deleted.
After screening the abstracts and titles, 200 articles were eliminated. One hundred and seventy (170) were removed because they were unrelated to the current research. Thirty (30) full-text papers were evaluated for eligibility. Nine papers were eliminated from the final data synthesis, leaving only 21 articles. The results are display in Figure 1.  Table 1

Publication bias assessment
No evidence of publication bias was found after symmetrical inspection using the funnel plot ( Figure 3) and egger's regression test (0.1654).

Sub-group analysis
As shown in Table 2 Table) Reasons

Discussion
The systematic review, and meta-analysis was carried out to ascertained the covid-19 vaccine acceptance rate, and possible reasons for the vaccine's hesitancy amongst HCWs in Africa. The data revealed generally low acceptance of the vaccine amongst HCWs care workers across Africa, and considerable covid-19 vaccine reluctance. The possible reasons for the vaccine hesitancy were; the side effects of the vaccine, concerns about the vaccine's safety, efficacy and effectiveness, short duration of the clinical trials, covid-19 infections, limited information, and social trust.
The overall acceptance rate for the covid-19 vaccination was 46% [95% CI: 37%-54%]. This is comparable to a previous systematic review and meta-analysis from the western world (14) and higher than a US observational based study (40). However, our estimate is lower than prior observational studies conducted in China (41) The study also revealed an estimated covid-19 vaccine acceptance rate of 34% [95% CI:29%-39%] by the healthcare students. The estimated value is lower than previous studies in Italy (47), US (48), and France (49). Complacency, exacerbated by low illness risk and low mortality in the continent since the epidemic began, could be contributing factors in this group of participants.
Certain common impediments to the acceptance of the vaccine seemed to be shared by HCWs across the continent. These included, side effects of vaccines, vaccine safety, efficacy and effectiveness of the vaccines, short duration of the clinical trials, the possibility of contracting Covid-19 infection from vaccines, limited information on the vaccines, and lack of social trust.
Vaccine hesitancy is mostly induced by the dissemination of misleading information, primarily through social media platforms and with the assistance of anti-vaccination organizations(50).
Biswas and colleagues conducted a scoping review analysis of 35 studies and found that HCWs worldwide have a 22.5% covid-19 reluctance rate on average. Their reasons for refusing the vaccination were identical to those revealed in this study (11).
In general, persuading individuals who are vaccine skeptics to change their beliefs is difficult, especially in a continent where there has been a history of vaccination resistance. Nevertheless, it's preferable to concentrate on disseminating positive and factual vaccine information while also strengthening healthcare workers' resistance to fraudulent information. Easy access and mandatory covid-19 vaccination policies in Africa is a good way to promote covid-19 immunization uptake.
Encouragement of vaccine production within Africa, and comparison of these vaccines with others produced outside the continent, could build more confidence in the safety and efficacy of vaccines among health care workers in the continent. This would involve isolating local strains of the virus to be used in the production of vaccines and the conduction of clinical trials among locals. The outcome of this will be, more tailored interventions to the fight against the pandemic on the continent and will bring the fight against Covid-19 nearer home. This will also help debunk unfavorable theories about the intents behind the production of vaccines. Finally, the onus is on governments and significant international stakeholders in the pandemic fight to utilize social media to educate the public, especially HCWs, on facts concerning vaccines in order to help debunk some claims made by conspiracy theorists This systematic review and meta-analysis have a number of limitations that should be acknowledged. First, the current review considered only English published papers and as a result some relevant articles maybe missed. Secondary, there was significant heterogeneity across the studies. Nevertheless, to the best of the authors' knowledge, this is the first systematic review and meta-analysis on covid-19 acceptance and hesitancy rate in Africa. The review used well-validated systematic review and meta-analysis models that are fully compliant with current international standards and recommendations. Sensitivity analyses were performed to determine the robustness of the estimates obtained from the meta-analysis

Conclusion
The result of this review revealed generally low acceptance of the Covid-19 vaccine amongst HCWs care workers across Africa. Major drivers and reasons were the side effects of the vaccine, vaccine's safety, efficacy and effectiveness, short duration of the clinical trials, covid-19 infections, limited information, and social trust. The willingness of HCWs to be vaccinated against COVID-19 acts as a valuable role model for the general public and hence, the misconceptions and barriers to covid-19 vaccine acceptance amongst these cadre of professionals must be addressed as soon as possible in the continent